SLCO1B1 (also known as OAT1B1) is an influx transporter that moves drugs into cells. Variations in SLCO1B1 may affect the blood levels of drugs that are substrates for this transporter. Statins are one of the most common classes of medications affected by this transporter, other medications include angiotensin-converting enzyme (ACE) inhibitors and methotrexate.
Variations that result in decreased transporter activity may result in increased statin blood levels and increase the risk of adverse effects, such as myalgia and rhabdomyolysis. SLCO1B1-based dosing guidelines are available for statins. Providers should consider genotyping patients who are initiating statin therapy or those who have experienced adverse effects to statins in the past. Genetic variants tested for SLCO1B1 are *1B,*5,*9,*14,*15,*17,*31,*35.
Indications for SLCO1B1 Testing
Any patient taking a simvastatin (Zocor®) dose of greater than or equal to 40 mg per day, or any individual with a personal or family history of adverse effects to medications that are substrates of SLCO1B1 are appropriate candidates for testing. Other statins that must be monitored closely and have their doses limited include atorvastatin (Lipitor®), rosuvastatin (Crestor®), pravastatin (Pravacol®) and lovastatin (Mevacor®). SLCO1B1 genotyping may also be useful in confirming the presence of variant genotypes that affect the metabolism of SLCO1B1 transported drugs.
Check with your insurance provider to see if SLCO1B1 testing is covered. The CPT code for SLCO1B1 testing is 81328 (provided for your guidance only).
Click here to order testing supplies or call Client Services at 800-837-8362.
- Buccal Swabs: 4 sterile buccal swabs
- Blood: 5-10cc whole blood lavender-top EDTA or yellow-top ACD-A tubes
- Turnaround Time: 10 business days, faster turnaround available for clinical trials